A Ford Escort car gifted as an engagement present by Prince Charles to the late Princess Diana is being sold at auction and could fetch up to $56,640.

The car is in excellent condition, with its original paint job and upholstery and a silver frog mascot on the bonnet – a copy of a gift from Diana’s sister, Lady Sarah Spencer.

The royal link means the 1981 Ford Escort MkIII Ghia 1.6L, with only 83,000 miles on the clock, could spark a bidding war among collectors.

The car disappeared from public view for more than 20 years, but its current owner always knew the Escort’s royal pedigree as she drove around Hertfordshire.

“Of course I knew when I bought it that it once belonged to Princess Diana. That is why I wanted it. I was a big fan of hers,” said Tina Kirkpatrick.

“I have driven it around as a second car ever since. A lot of people asked me why I had it and I used to tell them that it was my first car I passed my test in and that I was attached to it.

“I felt that its history and provenance were so unique and I didn’t want many people knowing.

“I have maintained it and had it regularly serviced and kept it in my garage. It is an excellent little runner and has always been reliable. I have had it for 20 years and now feel the time is right to sell it on.”